var searchInsert = function(nums, target) {
  let left = 0;
  let right = nums.length - 1;
  if(target < nums[left])
      return left;
  if(target > nums[right])
      return right+1;
  
  while(left < right){
      let mid = Math.floor(left+(right - left)/2);
      if(nums[mid] === target){
          return mid;
      }else if(nums[mid] < target){
          left = mid+1;
      }else{
          right = mid -1;
      }
  }
  return left;

};
console.log(searchInsert([1,3,5,6] ,2));